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Date:   Tue, 13 Jun 2023 12:26:28 -0700
From:   Kees Cook <keescook@chromium.org>
To:     Azeem Shaikh <azeemshaikh38@gmail.com>
Cc:     Pablo Neira Ayuso <pablo@netfilter.org>,
        Jozsef Kadlecsik <kadlec@netfilter.org>,
        Florian Westphal <fw@strlen.de>,
        linux-hardening@vger.kernel.org, netfilter-devel@vger.kernel.org,
        coreteam@netfilter.org, linux-kernel@vger.kernel.org,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>, netdev@vger.kernel.org
Subject: Re: [PATCH] netfilter: ipset: Replace strlcpy with strscpy
Message-ID: <202306131225.6EADAF4@keescook>
References: <20230613003437.3538694-1-azeemshaikh38@gmail.com>
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On Tue, Jun 13, 2023 at 12:34:37AM +0000, Azeem Shaikh wrote:
> strlcpy() reads the entire source buffer first.
> This read may exceed the destination size limit.
> This is both inefficient and can lead to linear read
> overflows if a source string is not NUL-terminated [1].
> In an effort to remove strlcpy() completely [2], replace
> strlcpy() here with strscpy().
> 
> Direct replacement is safe here since return value from all
> callers of STRLCPY macro were ignored.

Yeah, the macro name is probably not super helpful here. It seems like
it should have originally be named IFNAME_CPY or something.

> 
> [1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy
> [2] https://github.com/KSPP/linux/issues/89
> 
> Signed-off-by: Azeem Shaikh <azeemshaikh38@gmail.com>

But, regardless:

Reviewed-by: Kees Cook <keescook@chromium.org>

-- 
Kees Cook